Siemens SINUMERIK 840D sl Function Manual page 162

G1: Gantry axes
3.4 Start-up of gantry axes
Guide axis
MD32810 $MA_EQUIV_SPEEDCTRL_TIME [n] = 5 ms (equivalent time constant speed
control loop for feedforward control)
Synchronous axis
MD32810 $MA_EQUIV_SPEEDCTRL_TIME [n] = 3 ms
● Time constant of dynamic response adaptation for synchronous axis:
MD32910 $MA_DYN_MATCH_TIME [n] = 5 ms - 3 ms = 2 ms (time constant of dynamic
response adaptation)
The dynamic response adaptation must be activated axially with the machine data:
MD32900 $MA_DYN_MATCH_ENABLE (dynamic response adaptation)
Check of dynamic response adaptation:
The following errors of the guide and synchronous axes must be equal in magnitude when the
axes are operating at the same speed!
For the purpose of fine tuning, it may be necessary to adjust servo gain factors or feedforward
control parameters slightly to achieve an optimum result.
Referencing gantry axes
The positions of the guide and synchronous axes reference points must first be set to almost
identical values.
To ensure that the synchronization compensatory motion of the gantry axes is not started
automatically, the gantry warning limit must be set to 0 at the first start-up before referencing:
MD37100 $MA_GANTRY_POS_TOL (gantry axis definition)
This will prevent a warning message being output during traversing motion.
In cases where an excessively high additional torque is acting on the drives due to
misalignment between the guide and synchronous axes, the gantry grouping must be aligned
before the axes are traversed. After this, the gantry axes must be referenced. For further
details, see:
● Section "Referencing and synchronization of gantry axes (Page 150)"
● References: Basic Functions Function Manual; Reference Point Approach (R1)
After the guide and synchronous axes have been referenced, the difference between them
must be determined by comparing the actual position value (HMI: Operating area "Diagnostics"
> "Service axes") and taken into account as the reference point offset:
● MD34080 $MA_REFP_MOVE_DIST (reference point distance)
● MD34090 $MA_REFP_MOVE_DIST_CORR (reference point offset / absolute offset)
The differences in distance between the zero mark and reference point must also be calculated
for each gantry axis and adjusted. They are to be customized, via the following machine data,
in such a way that the actual position values of the guide and synchronous axes are identical
after execution of the compensatory motion:
● MD34080 $MA_REFP_MOVE_DIST (reference point distance)
● MD34090 $MA_REFP_MOVE_DIST_CORR (reference point offset / absolute offset)
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Function Manual, 01/2015, 6FC5397-2BP40-5BA2
Special functions